The stages of the present invention include blades which have a conventional twisted or cork-screw shape. They also include connection means fitted at or near the radially outer ends of the blades for making them integral with one another and preventing any rotation of a blade in either direction. Such means have been conventionally fitted to improve the vibration performance of the stage, and are particularly useful in the low pressure part of a turbine where the blades are longest.
When the turbine is in operation, forces are exerted on the blades which tend to make them straighten out or unwind their cork-screw shape (centrifugal force, driving fluid impact etc.). These rotary forces put a strain on the said connection means which can have undesirable effects on the connection means, the blades and any other stressed parts.